Topic: K7 no oil pressure

[kvikgrip68]

Hi Guys 

Im new here but not new into old Hondas 

Im working on a K7 from 77

Problem is that oil light wont go off when turning engine with the starter

following checked :
Oil pressure swich ok - out and checked with ohm meter and pressurized air
Wire to it - ok - light go off when wi :-[re is taken off from switch
Oil filter bolt is new
new filter
oil is sae 20w-50 mineral
Oil hoses from oil tank seems ok
sump cleaned up and oil pump out on table for excamination
its not worn out in rotors measured out for fine in specs an ( im in europe and its hard to find parts as orings seals and stuff for these pumps) if i buy from the US it costs a fortune in import TAX
I ve found some of the O rings but still missing the oring for the pressure relief valve parts not avaliable at cmsnl

[Deltarider]

Excuse me for not being very scientific here, but I do know sooner or later almost every CB Fours oil pressure switch becomes ineffective. My guess is that if we did a poll on this (your symptoms), the statistics would show the switch was mostly the culprit. It's a small investment to buy a new one and see what happens. It doesn't have to be genuine Honda. They're cheap. Don't overtighten on installing. They're not supposed to be screwed down. BTW, have you checked, after removing a tappet cover, oil reaches the cam?

[ekpent]

 You may need to put the oil pump in a container full of oil and prime it first or if your feeling brave just give it a go and start it up for real while looking into the oil tank for circulation/bubbles and other signs that oil is moving.
  Having the spark plugs out while spinning the engine with the starter button will make for less work on all the parts. Too late now but putting a quart of oil down the tappet holes when re-filling helps to get some oil down in a dry pan.

[Bankerdanny]

You can temporarily attach an automotive oil pressure gauge to find out if the issue is the sensor. On the top right side of the engine csse where the cylinder meets the case there is a tube about 1 inch in diameter with a cap that has a hex head. This is a port to the oil system. You can unscrew that, screw in the adapter that comes with the gauge then hook up the gauge. As Eric (Ekpent) said, pull the plugs so the engine spins faster, the starter should spin the engine fast enough for there to be visible oil pressure.

[Jerry Rxman Griffin aka MuthaF'er]

Does it go out when the engine starts?!

[kvikgrip68]

Thanks for advices :


New oil switch installed with no difference

I have no oil pressure gauge at my hand would like one installed at the oil gallery on the side but can only find the damn thing in the US

Im working on the pump now …….as i wrote specs are fine but maybe some new o rings does the trick  ….maybe its the pressure relief valve that Sticks ? ….but really hard to get parts and still looking for a decent internet store except for cmsnl of course ...

[ekpent]

 So have you ever started or heard the engine run yet or is this a project you have rebuilt/worked on to get to this point ? 

[flybox1]

So have you ever started or heard the engine run yet or is this a project you have rebuilt/worked on to get to this point ?

+1
If this is the case, pour a quart of oil thru the tappet holes and start the bike.
If the light doesnt go out after 10 seconds, shut it off.  Enough oil will be up top to keep everything wet.

[kvikgrip68]

Engine is in frame and didnt run since 1990   I ve cleaned up sump and put new oil on -
ok ….i started the bike only 1 time and noticed the issue with lamp not go off ….now im in for the pump and when its finished i will put it on Again and try once more .

the pump was full of oil when taking it off and it seems like it was pumping .....so my question is .....why isnt there any oil up at the oil gallery near the switch ?

[Jerry Rxman Griffin aka MuthaF'er]

Take off a tappet cover or 2, start it and watch for oil flow.

[tlbranth]

So have you ever started or heard the engine run yet or is this a project you have rebuilt/worked on to get to this point ?

+1
If this is the case, pour a quart of oil thru the tappet holes and start the bike.
If the light doesnt go out after 10 seconds, shut it off.  Enough oil will be up top to keep everything wet.

Jeez fly, that won't do much for the bearings

[PeWe]

Recent oil drainage and refill.
My engine needed >20 sec running on starter to get pressure enough for oil pressure warning to go off.

[rotortiller]

why isnt there any oil up at the oil gallery near the switch

Make sure there is oil being supplied to the engine oil inlet port from the oil tank supply line. Seeing how you have little in the way of tooling maybe take the plug out of the gallery when it is idling or on the starter to see if it has any oil being pumped. That will tell you  something. You could take a squirt can of oil to it too and manually lube the gallery for extra insurance while on the side-stand as any oil dribble is better than none during a short duration test. Then make the call to go and buy a gauge and adapt it. If you checked the oil gallery during engine rpm already then ignore the suggestion as it might be a serious job and you may actually have to blast LOL

[754]

You should be able to take the cap off near point cover, lean the bike over,  pour in some oil and get it to the bearings I think.
 They should be wet anyway.
 If you leave the cap a bit loose you should see oil coming out quickly, then snug it up.

[kvikgrip68]

Hey everybody

Thanks for help and advices
Finally i got pressure on the sucker New O rings and priming before reinstalling did the job 

[Don R]

 Thanks for the report!